Automatic Call Distributors (ACDs) provide a capability that is frequently designed into Private Branch Exchange (PBX) equipment, that routes incoming telephone calls to selected destinations. Many relatively large companies provide call-in service for the convenience of their customers and potential customers. Reservation and information services provided by many airlines are familiar examples. Typically, such companies maintain one or more ACDs that route calls to various agents according to the particular telephone number dialed. In one system, calls to each particular telephone number are routed to a group of agents who possess skills needed for handling calls to that number. Calls to each particular number are placed in a queue and served in sequence according to the order in which they are received. Frequently one queue is long when another is empty, and it is known to allow agents who possess multiple skills to handle several queues. Indeed, in some systems each agent handles up to three types of calls. Unfortunately, this "one-to-many" scheme has its limitations. It is inefficient to assign agents to multiple queues where each queue identifies the same apparent need of the caller, because other needs are overlooked which may be useful in completing the call in a timely manner.
In another system, each agent is associated with a particular type of call, and each call is placed in several queues. This "many-to-one" scheme is also limited. Here, load sharing among agents requires that calls be initially queued to those agents having predetermined specific skills. Like the first described system, success in matching caller needs with available skills requires either a large pool of agents or suffers long waiting times. Thus, assigning incoming calls to multiple queues, each exclusively served by a specific agent, has the disadvantage that the agent is inefficiently utilized because only one of his/her skills is activated.
Both of the above-described systems are quite similar since, for example, it makes little difference whether each caller is placed in three queues--each queue being served by a single group of agents, or whether each caller is placed in a single queue served by three groups of agents. So long as callers are assigned to queues with little regard for their specific needs, or agent skills are rigidly administered, there is little guarantee that the best tradeoff can be made in matching agents with callers in minimum time.
In the business information environment, agents are grouped according to their skills. Companies that provide agent services are not only concerned with matching customer needs and agent skills, but also with minimizing the number of agents (and hence expenses). The effective utilization of agents within and between groups thereof, while matching callers and agents in a timely manner, is a well-known problem in the industry.